This guy tested a $100 solar panel and windmill and found the solar panel was much, much better. https://youtu.be/iHulKsD35Hc

This guy gets into the math behind the Tesup Atlas wind turbine. Basically the real output people are getting could be matched by 200-400watts of solar. https://youtu.be/6ixUmlN-cYc

The 2 biggest problems with scaling down turbines.

1. Hard 60% efficiency limit called the Betz Limit

2. Wear and tear on smaller parts is the same as bigger parts but with lower output efficiency.

I guess a 3rd is that the surface area to volume ratio is probably what makes large turbines practical in the first place.